Utilization of the Contralateral Transmaxillary Approach for Chordoma and Chondrosarcoma of the Petrous Apex

Background The endoscopic endonasal approach (EEA) has been shown to be an effective means of accessing lesions of the petrous apex. Lesions that are lateral to the paraclival internal carotid artery (ICA) are challenging to access and require mobilization of the paraclival ICA. Recently, we described the contralateral transmaxillary (CTM) approach for improved access to the petrous apex. Here, we present our clinical experience utilizing the CTM approach.

Methods A retrospective chart review was performed to identify patients who underwent surgery utilizing the CTM approach at the University of Pittsburgh Medical Center.

Results At present time, seven patients were identified who had undergone the CTM approach. The mean patient age was 55 years. All patients had a diagnosis of skull base chordoma (four) or chondrosarcoma (three) involving, but not limited to, the petrous apex. The most common initial presenting complaint was diplopia (seven out of seven). A majority of cases (five out of seven) were recurrences and had previously undergone surgery with adjuvant radiation. The CTM approach was most commonly used in conjunction with transclival (seven out of seven), transpterygoid (six out of seven), and medial maxillectomy (three out of seven) approaches. Mobilization of the pterygopalatine fossa on the side ipsilateral to the CTM approach was necessary in one out of seven cases. Sacrifice of the vidian nerve on the side contralateral to the CTM approach was necessary only when a transpterygoid approach was used and was not necessary for CTM approach alone. Nasal septal flaps were used in six out of seven cases with four out of six being harvested ipsilateral to the CTM approach and two out of six contralateral to the CTM approach. Flap harvest and viability were not affected by the CTM approach. Gross total resection was achieved in five out of seven cases. The CTM was subjectively found to extend the ability to resect extensive lesions of the petrous apex in all cases, due to improved lateral trajectory, allowing less manipulation of the paraclival ICA and improved drilling angle. The anatomical limits of the CTM approach were due to tumor extension beyond the petrous apex. There was one complication attributable to the CTM approach (sensorineural hearing loss due to cochlear nerve injury from the use of ultrasonic aspirator near internal auditory canal [IAC]). There were no cosmetic defects related to the CTM approach noted postoperatively.

Conclusion The CTM approach is a feasible extension to standard EEA approaches to the petrous apex that offers a more lateral trajectory with improved access and limited additional morbidity. The CTM approach can provide access as far lateral as the IAC and first genu of the ICA. It is ideally suited for infiltrative bone neoplasms such as chordomas and chondrosarcomas.